向海湿地自然保护区鸟类多样性评价方法的比较研究

鸟类多样性是评价湿地生态环境质量极其敏感的指标。向海湿地自然保护区地处半干旱区,受气候和人为影响,生态环境变化极为剧烈,因此,寻求一种行之有效且简单易行的鸟类多样性评价手段,对于及时了解湿地生态环境质量的动态变化信息,提出湿地和鸟类多样性的管理和保护对策至关重要。稀疏标准化法是一种建立在物种-面积关系上的生物多样性评价方法,主要用于区域尺度上的生物多样性评估。运用改进的稀疏标准化程序,利用多年调查和收集的鸟类数据,来评价和分析向海自然保护区鸟类多样性及其变化,结合香农-威纳多样性指数和均匀度指数,分析了两种方法获取结果的相关性。评估结果表明:稀疏标准化法获取的鸟类多样性和均匀度信息与传统的香农-威纳多样性指数和Pielou均匀度指数间具有显著的相关关系,可以用于鸟类的多样性和均匀度评价,且具有科学、直观、运算简捷、快速等优势。     

Pedodiversity: a controversial concept

The concept of pedodiversity and its measurement methodology proposed and developed by Ibá?ez research term is introduced. An attempt to apply pedodiversity to analyze spatial soil variation and distribution patterns on the global scale is briefly demonstrated. Furthermore, constructive comments and criticisms on pedodiversity and its measurement from the noted pedologists and ecologists are outlined. Finally, potential applications of pedodiversity in soil science and other relevant disciplines are discussed.     

无砟轨道基桩控制网测量技术探讨

轨道的高平顺性是客运专线无砟轨道最突出的特点之一。因此,需要建立高精度的铺轨基桩控制网。基桩控制网通常是按五等导线测量的方法进行布设,本文提出在导线基础上采用边角后方交会法来加密,通过运用原始数据误差理论和仿真实验的方法对无砟轨道控制基桩网的新旧两种测量技术进行对比,结果显示:采用边角后方交会法加密的控制网将得到更高的相对点位精度,具有更好的平顺性指标。这一结论对我国客运专线无砟轨道施工控制网的建设或许有参考价值。     

Fishery resources in arid zone mangroves in gulf of Kachchh, Gujarat, northwest coast of India

The finfish and shellfish resources were assessed quantitatively and qualitatively in regard to their abundance in creek waters at three sites within a period of two years, from January 1999 to December 2000, in the western mangrove areas of Kachchh. The catch rate varied from 0.69 to 6.99 kg h⁻¹. It was low during monsoon (July to October), which could be due to the freshwater-flow-induced salinity reduction in all the sites. Among 38 species recorded, 5 were shellfish and 33 were finfish. The spawning period of fishes was found to be during summer and early monsoon period (May to August). Surface water temperatures varied from 17 °C to 37 °C. Salinity values varied from 34 to 44 and the pH ranged between 7 and 8.9. Variation in dissolved oxygen content was from 3.42 to 5.85 mL L⁻¹. The high fishery densities in these semi arid mangrove creek areas were recorded during monsoon and early winter season.     

南澎列岛近海海域底拖网鱼类组成的季节性变化

1991年逐月对南澎列岛近海海域作底拖网调查,共捕获鱼类132种,其中软骨鱼类7种（4目6科6属）,硬骨鱼类125种（10目58科95属）,后 者以鲈形目居多（69种）。全年渔获优质种类为条尾鲱鲤、黑天竺鱼、二长棘鲷、大头狗母鱼、多齿蛇鲻、三线矶鲈、绿布氏筋鱼、多鳞Xi和乔氏台雅鱼等9种,其渔获尾数之和是渔获总数的71．1％。季节性优势种类除全年优势种类外,尚有粗纹Fu、半线天竺鲷、印白姑鱼、静Fu和翼红娘鱼等5种;各种类全的渔获尾数及出现月份数相关,各月份的渔获尾数和渔获种数不相关;渔获物中仅有少量的中上层鱼类（13种）。就适温性而言,该海区鱼类以亚热带性为主并兼有热带性特征,以Shannon、Brillouin、Simpson和McIn-tosh等多样性指标及相应的Hurlbert均匀度指标对逐月样本做估计,这8种指标之间高度显著相关;该海域鱼类的Shannon多样性指标及相应的均匀度指标皆以秋冬季为高,春夏季较低。     

Stomach content analysis of juvenile Cape stumpnose Rhabdosargus holubi in the Swartkops Estuary,South Africa

Stomach content analyses were performed on the Cape stumpnose Rhabdosargus holubi. The contents were identified to species level and the dietary importance of each component assessed by employing unrelated quantifying methods, which were subsequently combined to determine an index of relative importance (IRI). The index was determined on a seasonal basis as well as for individual sampling stations. The aquatic macrophyte Zostera capensis was the single most abundant item and, together with filamentous algae, constituted the major proportion (IRI = 7 314) of the diet. Crustacea were the next most abundant (IRI = 6 534), followed by Mollusca (IRI = 160). Stomach contents from the sampling stations in the lower reaches were dominated by aquatic macrophytes and algae, whereas those from the middle and upper reaches had a higher incidence of Crustacea. Mollusca in the diet were uniformly distributed throughout the estuary. There was considerable flexibility in the feeding pattern of R. holubi.     

五台山冰缘地貌植物群落多样性分析

采用双向指示种分析法(TWINSPAN),将五台山7个冰缘地貌的植物群落划分为13个群丛.不同冰缘地貌植物群落类型的组成多样性有明显差异,根据13个群丛在不同冰缘地貌的分布状况,可区分为共有性群丛和专有性群丛.运用丰富度指数、物种多样性指数和均匀度指数对五台山7个冰缘地貌的综合群落多样性指数变化进行了分析,依据不同冰缘地貌植物群落综合多样性指数的大小排序,依次为冻融草丘石海石环冻融剥蚀面石河岩柱泥流坡坎和泥流舌.冰缘地貌的海拔、土层厚度、水分热量是影响植物群落植物种多样性指数变化的主要因素.     

A Local Multidimensional Approach to Evaluate Changes in Segregation

This paper demonstrates a local approach to assess changes in segregation at the neighborhood scale. Many studies on segregation change were conducted at a regional or city scale using a single measure. This approach is not sufficient to document the process of neighborhood change, and using one measure can reflect only a single dimension of multifaceted segregation. In this article, several local measures related to two segregation dimensions are utilized to compare segregation levels between the three census years of 1980, 1990, and 2000. Using Buffalo, New York, as the case study, I show that the local approach is effective in depicting the varying levels of segregation within a city for a given year as well as changes in neighborhood segregation levels over time. Overall, the local multidimensional approach offers an effective way of identifying neighborhood demographic transformation and detecting varied trajectories of neighborhood change across a metropolitan area.     

Pedodiversity: a controversial concept

1 Conceptual introductionSpatial soil variation is a fundamental notion of pedology, formally expressed in the hierarchical system of soil taxonomy and soil associations[1,2]. Since the 1990s, a Spanish research team led by Ibá?ez has been presenting a possible approach to systematically analyze taxonomic diversity of pedosphere by methods employed in ecological studies, drawing a parallel with the concept of biodiversity in ecology. According to Ibá?ez et al., it would be quite reasonable …     

Predictability of Functional Diversity Depends on the Number of Traits

Analysis of functional diversity, based on plant traits and community structure, provides a promising approach for exploration of the adaptive strategies of plants and the relationship between plant traits and ecosystem functioning. However, it is unclear how the number of plant traits included influences functional diversity, and whether or not there are quantitatively dependent traits. This information is fundamental to the correct use of functional diversity metrics. Here, we measured 34 traits of 366 plant species in nine forests from the tropical to boreal zones in China. These traits were used to calculate seven functional diversity metrics: functional richness (functional attribute diversity (FAD), modified FAD (MFAD), convex hull hypervolume (FRic)), functional evenness (FEve), and functional divergence (functional divergence (FDiv), functional dispersion (FDis), quadratic entropy (RaoQ)). Functional richness metrics increased with an increase in trait number, whereas the relationships between the trait divergence indexes (FDiv and FDis) and trait number were inconsistent. Four of the seven functional diversity indexes (FAD, MFAD, FRic, and RaoQ) were comparable with those in previous studies, showing predictable trends with a change in trait number. We verified our hypothesis that the number of traits strongly influences functional diversity. The relationships between these predictable functional diversity metrics and the number of traits facilitated the development of a standard protocol to enhance comparability across different studies. These findings can support integration of functional diversity index data from different studies at the site to the regional scale, and they focus attention on the influence of quantitative selection of traits on functional diversity analysis.